1. Field of the Invention
This invention relates generally to radar decoys and more particularly to such a decoy having means for varying its scintillation magnitude or scintillation rate.
2. Prior Art
A variety of techniques have been devised to modify or reduce the radar cross-section or signature of a space target, such as a missile or satellite, to prevent its identification by search radar. Modification of the target's signature in many cases is not totally effective, and therefore target simulators or decoys are used to further inhibit indentification of the real target. In order to be effective for this purpose, the decoy must duplicate the target vehicle's radar cross-section or signature, as well as its speed and body motions. Targets of appreciable size such as spacecraft have a broad band frequency response which necessitates a target simulator or decoy of similar band width.
The radar cross-section of a typical decoy is aspect sensitive. That is to say, a decoy, when illuminated by a radar beam, exhibits variations, termed scintillation, due to its body motion as seen from the radar site. If this variation or scintillation is sufficiently unlike that of the target, a basis for discrimination exists and the effectiveness of the decoy is substantially reduced. In general, scintillation is also dependent upon the frequency of the illuminating radar, with higher radar frequencies resulting in higher scintillation rate.